EngineMedium
1.5T carbon build-up / oil consumption.
- Typically appears
- 60,000+ miles
- What to inspect
- Check oil level and watch for rough idle.
2018–2023 GMC Terrain · common problems & known faults
The 2nd-gen Terrain uses small turbo engines; carbon build-up and the 9-speed are the main checks.
Compiled & reviewed by the VehicleFaults Research Team · last reviewed July 2026
Quick answer
The most commonly reported faults on the 2018–2023 GMC Terrain are 1.5T carbon build-up / oil consumption, 9-speed shudder and shift-to-park glitch and AC condenser faults. Most reported issues are medium or low severity, but a pre-purchase inspection is still recommended. Full inspection points, onset mileage and what to check are listed below.
Reliability snapshot
Based on the documented faults on this page for the GMC Terrain.
8.1/ 10
- Critical
- 0
- High
- 0
- Medium
- 3
- Low
- 1
Guidance only · reflects reported patterns, not a specific car's condition.
Known faults to check
TransmissionMedium
9-speed shudder and shift-to-park glitch.
- Typically appears
- Any
- What to inspect
- Feel for shudder and confirm clean park engagement.
HVACMedium
AC condenser faults.
- Typically appears
- 70,000+ miles
- What to inspect
- Confirm cold AC output.
ElectricalLow
Stabilitrak / infotainment glitches.
- Typically appears
- Age-related
- What to inspect
- Watch for warnings and test the screen.
Inspecting a GMC Terrain?
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Check this exact carFrequently asked questions
Is the Terrain reliable?
Average — turbo carbon build-up and 9-speed behaviour are the usual concerns.
Is the 1.5T strong enough?
It's adequate for daily driving; the 2.0T is livelier if you tow or load it.
Does the Terrain have the shift-to-park fault?
Some do; confirm it engages park without a persistent warning.
Sources & further reading
Faults are compiled from documented recalls, technical bulletins, owner reports and mechanic sources, then reviewed for accuracy. This is guidance only · not a substitute for a professional inspection.